The development and change over time (evolution) of geomorphic, soil, hydrological, and ecosystems (Earth surface systems; ESS) is often, perhaps mostly, characterized by multiple potential developmental trajectories. That is, rather than an inevitable monotonic progression toward a single stable state or climax or mature form, often there exist multiple stable states or potentially unstable outcomes, and multiple possible developmental pathways. Until late in the 20th century, basic tenets of geosciences, ecology, and pedology emphasized single-path, single-outcome conceptual models such as classical vegetation succession; development of mature, climax, or zonal soils; or attainment of steady-state or some other form of stable equilibrium. As evidence accumulated of ESS evolution with, e.g., nonequilibrium dynamics, alternative stable states, divergent evolution, and path dependency, the "headline" was the existence of > 2 potential pathways, contesting and contrasting with the single-path frameworks. Now it is appropriate to address the question of why the number of actually observed pathways is relatively small.The purpose of this post is to explore why some developmental sequences are rare vs. common; why some are non-recurring (path extinction), and some are reinforced.

In a 2009 article I introduced the concept of a geomorphological niche, defined as the resources available to drive or support a particular geomorphic process (the concept has not caught on). The niche is defined in terms of a landscape evolution space (LES), given by

where H is height above a base level, rho is the density of the geological parent material, g is the gravity constant, and A is surface area. The k’s are factors representing the inputs of solar energy and precipitation, and Pgrepresents the geomorphically significant proportion of biological productivity (see this for the background and justification).

The New Maps Plus graduate programs at the University of Kentucky offer students a challenging, intensive, digital mapping curriculum that emphasizes the acquisition of technical skills—coding, GIS, web development—while also preparing students to critically address the complexity of today’s information ecosystem.

The University of Kentucky College of Arts and Scienceslast week hosted the Summer Institute in Economic Geography. With a 10-year history in supporting economic geography, the college and its Department of Geography welcomed young scholars from across the globe to Lexington. This is the first time the institute has returned to the U.S. since 2006 when it was hosted by the University of Wisconsin at Madison.

The 22nd annual Conference on Critical Geography was hosted at the University of Kentucky this past October. In between sessions, conference participants had the opportunity to participate in a video booth project, titled Love Is.... Here, participants were asked to share their thoughts and opinions on the nature of love.